The present invention relates to the detection of microorganisms in a fluid sample such as, for example, body fluids.
The detection of microorganisms in body fluids, particularly bacterial in blood, requires that a sample of the fluid be used to inoculate a liquid nutrient medium. Subsequently, the liquid medium is in turn used to inoculate a solid medium to continue the growth of the organisms. For years, there have been in use detection systems in which both liquid and solid culture media are combined in the same container. Such systems avoid the troublesome and sometimes hazardous transfer of the precultures, i.e., the liquid medium, to the solid culture medium outside the container.
Such devices, i.e., those combining the liquid and solid media in a single container are not satisfactory for many reasons. In particular, because of the hazards inherent in constituents of the solid medium dissolving into the liquid medium, only solid media compatible with the liquid medium can be utilized. One of the major disadvantages of solid media constituents passing into the liquid media is that, when it occurs, differentiations of the pathogens may no longer be possible.
The solutions suggested to date for separating solid and liquid culture media are complicated, time-consuming, costly and/or facilitate separation of the media only during incubation, but not during tranport.
The above disadvantages of prior art methods are overcome in accordance with the present invention which provides a device whereby solid and liquid culture media are transported separately to the user or to a place of further processing after inoculation. The device of the present invention, however, provides for inoculation of the solid nutrient medium with the liquid medium as in conventional double culture bottles, i.e., by simply shaking and flooding the surface of the solid medium with the liquid medium.